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In late 2005, researchers at the Royal College of Surgeons in Dublin made public a new procedure that used a blood test and an ultrasound to reliably predict if a baby would be born with Downs syndrome as early as 11 weeks into a pregnancy.

The massive research project had sought to determine which method from the dizzying array available provided the most accurate information, soonest, to pregnant women.

The ultrasound-blood test combination identified about 87 per cent of Downs babies in the first trimester. With follow-up testing early in the second trimester, the detection rate jumped to 96 per cent.

Current standard screening for Down's involves a blood test, with an 81-per-cent detection rate, done in the second trimester.

The early test, carried out at about 11 weeks into gestation, uses an ultrasound exam called nuchal translucency to measure the thickness of skin on the neck of the fetus. Two blood tests measure for a protein called pregnancy-associated plasma protein A (PAPP-A) and a hormone called human chorionic gonadotropin (HCG).

If the results are worrisome, a procedure called chorionic villus sampling (CVS) takes a tiny tissue sample from the sac where the baby develops using a small tube snaked through the cervix.

Alternatively, women get another series of four blood tests conducted in the second trimester.

That so-called quadruple test -- which is the standard method in most of Canada --involves looking for biological markers of Down syndrome. Only if that test is positive should a woman undergo amniocentesis.

Until the early 1980s, the only way of detecting Down syndrome and other chromosomal abnormalities was amniocentesis, a test that involves extracting amniotic fluid from the uterus with a long needle. The test can trigger a miscarriage, but was recommended for all pregnant women over 35.

Down syndrome, a genetic condition, occurs in about one in every 800 live births. People with Down's have extra genetic material on chromosome 21, abnormalities that can cause physical ailments and developmental delays. There are about 30,000 Canadians living with Down syndrome.